As reported on Wim Schermer’s blog the K_Drive elliptical crank system is to be made available by Alligt, the manufacturer of the Alleweder and Sunrider family of velomobiles. Alligt intends to present the new drive at the 7th international Velomobile Seminar in a few weeks time.

Like many, if not all, modern innovations in cycle technology the K-Drive can be traced back to the period of intense creativity in the late 1800s. The modern form was developed by Miles Kingsbury and successfully used on the Kingcycle but the mechanism itself appears to have been first described in 1890.

The renewed interest, which has lead Alligt to start production, came from the University of Delft’s current attempt on the Human Powered Land Speed Record with their VeloX 2 HPV. To optimize aerodynamics the Human Power Team’s research and experience with VeloX 1, lead them to conclude that the way forward is to significantly reduce the frontal cross section of the nose. However the size of this section is determined largely by the swept volume required for the cranks, pedals and feet of the rider. It therefore became necessary to develop a transmission that could reduce the vertical dimension of this volume. Patrick Fenner of Deferred Procrastination calculates this reduction to be of the order of 45%. His post on the K-Drive gives a good overview and also includes a demonstration video of the Human Power Team’s drive in motion. Of course the proof of the pudding will be in the eating with 26 days to go till the test at Battle Mountain.

Alligt already produce a nice collection of specialist parts for recumbents and velomobiles and this should prove useful home builders and potentially commercial manufactures who are looking to emulate the approach of the Human Power Team and VeloX 2.